A detailed survey of energy use and related physical and operational characteristics of Florida's public schools was completed. A mailed survey instrument was sent to all 2,512 schools through out the state in March 1996. A total of 1,298 surveys were returned -- a response rate of 52%. Of these, some 680 provided matching utility data. The survey data was analyzed to create a school energy use profile as well as to identify characteristics that may influence efficiency. A typical Florida school uses 1.4 million kWh and 7,400 therms of natural gas at an annual expense of $94,000 per year (1.24 Btu/ft2). Based on our findings, the total annual energy cost for the Florida school system totaled $205 million in 1995.
The objectives of this study were:
- To develop detailed information on the characteristics of Florida schools
which might have energy implications.
- To develop ranking of schools based on relative energy use.
- To analyze the statistical association of school characteristics and energy use.
The principal yardstick used in this analysis is that of energy used per square foot of air conditioned floor area, or Energy Use Index:
EUI = Annual Energy Use (kBtu) / Facility Floor Area (ft2)
This measure allows comparison of schools to determine those with the largest opportunities for savings.
We ranked schools with complete data (654 facilities) by their energy use per square foot, or Energy Use Index (EUI, kBtu/ft2). The EUI's varied from 2 - 226 kBtu/ft2. The 10% of schools who used the most energy per square foot were identified as potential candidates for future improvement projects.
Histogram of energy use index (EUI) for all schools
Finally, an analysis was performed of the statistical influences on energy use in schools based on the responses to the survey questionnaire against the matched utility data. The analysis showed some surprising influences:
Relationship of annual electricity use to floor area by school type
Issues statistically linked to perceived indoor air quality problems: